PowerShell Defrag Analysis returning NULL values

Question

PowerShell Defrag Analysis returning NULL values

$computer = "Server"
$drives = Invoke-Command -ComputerName $computer -ScriptBlock { Get-PSDrive -PSProvider FileSystem | Select-Object @{n = "Name"; e = { $_.Root.TrimEnd("\") } } }
$drives.Name | ForEach-Object {
    Write-Host $_
    Invoke-Command -ComputerName $computer -ScriptBlock { param($_) 
        $volume = Get-WmiObject -Class Win32_Volume -Filter "DriveLetter = '$_'"
        Write-Host $volume
        $fragmentation = $volume.DefragAnalysis() 
        $Props = @{
            FragmentationStatusFor = $($volume.Name)
            TotalFragmentedFiles   = $($fragmentation.TotalFiles)
            TotalFragmentedBytes   = $($fragmentation.TotalBytes)
        }
        New-Object -TypeName PSObject -Property $Props
    } -ArgumentList $_, $volume
} | Select-Object * | Write-DbaDataTable -SqlInstance SomeServer -Database SomeDB -Schema GET -Table DbaDefragAnalysis -AutoCreateTable -Confirm -KeepNulls -bulkCopyTimeOut 180 -ErrorAction Continue -Verbose -EnableException;

TotalFragmentedFiles returns no value TotalFragmentedBytes returns no value

Answer 1

You are trying to retrieve a property of the Win32_DefragAnalysis WMI class that do not exist, check the Microsoft Documentation for Win32_DefragAnalysis, there is no property called TotalBytes, that's why you are getting no return values.

To get the values that you are trying to fetch, you should probably follow this article of the MS documentation